Keyseat wiper



March 11, 1969 D. D. WEBB 3,431,990

KEYSEAT WIPER Filed Feb. 2, 1967 Sheet L of 2 DERREL D. WEBB T INVENTOR.

/ BY fi 460 M g-M United States Patent 3 Claims ABSTRACT OF THE DISCLOSURE A keyseat wiper comprising a tubular member connectible in a drill string and a sleeve about an intermediate portion of the member. The sleeve is shorter than the distance between jarring shoulders on opposite ends of the member and has spirally arranged wiper blades on its outer surface. A longitudinal spline on the sleeve has notches adapted to be selectively engaged by lugs of a longitudinal spline on the tubular member in alternate axial positions of the member within the sleeve. The tubular member spline is held engaged with the sleeve spline in either position by right hand torque applied to the member, and is disengaged to permit the member to move axially within the sleeve when torque is released.

This invention relates to improvements in keyseat wipers.

In the drilling of a well, there is a tendency for the drill string to bend and thus rub against a side of the well bore. This may form a notch or keyseat laterally of the bore, which is narrower than the larger parts of the drill string, such as the drill collars above the bit. Consequently, the drill string may become stuck in the keyseat during a round tripi.e., as the string is raised to the wellhead.

A keyseat wiper is a tool adapted to be connected in the drill string for the purpose of preventing the string from becoming so stuck. In its most common form, it comprises a tubular member adapted to be fixedly connected as a part of the drill string above the drill collars and having cutting blades disposed thereabout, usually in a spiral pattern. More particularly, the outer diameter of the blades is larger than the remainder of the drill string above the bit, so that, as the string'is raised, the blades will engage the keyseat and ream it out to such diameter by a reciprocation of the string. Then, of course, the smaller diameter portion of the string is free to pass through the keyseat.

One problem with the use of this conventional type of keyseat wiper is its tendency to become stuck in the keyseat, and it has therefore been proposed to provide keyseat wipers with means for jarring the blades loose from the keyseat. As shown, for example, is Burris Reissue Patent No. 23,860, blades are formed on a sleeve disposed about a tubular member connected as a part of the drill string and intermediate jarring shoulders on opposite ends of the tubular member. Thus, the tubular member may be reciprocated in a well known manner to jar up or down on the ends of the sleeve.

It has also been proposed to provide keyseat wipers with so-called detent type jars in which energy may be stored in the tubular member and then released, so as to jar with greater force than is possible with the simple jar mechanism above-described. Thus, for example, as shown in Van Note Patent No. 2,821,363, the tubular member may have a lug for fitting within a notch in the sleeve in a raised position of the member relative to the sleeve. With torque held upon the member to retain the lug in the notch, the weight of the string may be slacked off so as to store energy therein. Then, upon release of the torque, this energy causes the member to jar down on the sleeve with a large impact.

However, in the tool shown in Patent No. 2,821,363, there is no way to jar the wiper blades up as well as down. Also, when torque on the tubular member is released to permit it to jar down on the Wiper blade sleeve, the lug moves downwardly through a slot in the lower end of the sleeve. Consequently, in this latter position, there is no rotary drive connection between the tubular member and sleeve and thus no way to drill out ledges or other obstructions in the bore or to Wash over the tool in the event it is held against rotation. Still further, in this tool, the wiper sleeve comprises arcuate parts which are Welded about the tubular member. This not only makes it impractical to replace the sleeve in the field when the blades wear down, but also upsets heat treating of the tubular member.

In tools of the type above described, comprising concentrically arranged and relatively reciprocable tubular parts, there is a tendency for drilling mud and debris within the annulus between the tool and the well bore to accumulate between the parts. When this occurs, the outside part or wiper sleeve may become frozen with respect to the tubular member, thereby making it impossible to effect a jar. This problem is aggravated by the practice of starting the mud pumps to circulate the mud during a jarring operation. Thus, with the wiper sleeve jammed tightly within the keyseat, the circulating mud is effectively restricted to passage between the tubular member and sleeve.

An object of this invention is to provide a keyseat wiper in which energy may be stored to deliver heavy jars to the wiper blades in either direction and in which there is a rotary drive connection between the tubular member and the wiper blade sleeve in all vertical positions thereof relative to one another.

It is a more particular object to provide such a keyseat wiper in which such jars may be delivered by a detent mechanism of the type above described.

Another object is to provide such a keyseat wiper in which the wiper blade sleeve is not welded about the tubular member at the time of construction.

Still another object is to provide a keyseat wi-per of the character described above in which the wiper blade sleeve will not freeze on the tubular member; and, more particularly, in which mud and other debris is effectively excluded from accumulating between the sleeve and tubular member.

These and other objects are accomplished, in accordance with the illustrated embodiment of the invention, by a keyseat wiper comprising a tubular member having blades about its outer surface and adapted to be connected in the drill string, and a sleeve disposed about the tubular member intermediate longitudinally spaced shoulders about the tubular member, whereby each end of the sleeve is adapted to be jarred by a shoulder on the tubular member. A spline extending longitudinally along the inside of the sleeve has notches along one side of it, and

a spline extending longitudinally along the outside of the tubular member has at least one lug on it for selective engagement with a notch of the spline on the sleeve. Upon application of torque to the tubular member in one direction, the sleeve and tubular member may be held against relative movement, and upon release of the torque, the splines disengage to permit the tubular member to move axially of the sleeve. Thus, energy stored in the drill string is free to urge one of its shoulders against an end of the sleeve with a jarring impact.

The tubular member includes a tublular section having an enlarged end providing one of the shoulders and a sub which is removably connected about the opposite end of the tubular section to provide the other shoulder. The sleeve includes an integral member movable axially over the opposite end of the tubular section when the sleeve is disconnected from it. The sleeve has reduced inner diameter portions on its opposite ends, the first tubular member has equal outer diameter portions above and below the spline thereon, and a means is provided on the reduced inner diameter portions of the sleeve for sealing about the equal diameter portions on the tubular section, whereby mud and debris is excluded from the annular space between the sleeve and tubular member.

These and other objects, advantages, and features of the invention will be apparent to those skilled in the art from a consideration of this specification, attached drawings and appended claims.

In the drawings, wherein like reference characters are used to designate like parts:

FIGURE 1 is an elevational view of a keyseat wiper constructed in accordance with the present invention and with the wiper blade sleeve thereof located within a keyseat;

FIGURE 2 is a longitudinal sectional view of the keyseat wiper shown in FIGURE 1, with the tubular member thereof in a raised position relative to the sleeve and upon the application of torque thereto so as to engage a detent between the tubular member and sleeve in preparation for imparting a downward jar to the sleeve;

FIGURE 3 is a cross sectional view of the keyseat wiper, as seen along broken line 3-3 of FIGURE 2;

FIGURE 4 is a cross sectional view of the keyseat wiper as seen along broken line 44 of FIGURE 2;

FIGURE 5 is a longitudinal cross sectional view of the sleeve with the tubular member removed therefrom; and

FIGURE 6 is an elevational view of an intermediate portion of the tubular member removed from within the sleeve.

With reference now to the details of the above described drawings, the keyseat wiper shown in its entirety in FIGURES 1 and 2, and designated by reference character 10, comprises a tubular member 11 connected as part of a drill string extending into the wall bore 12 and a sleeve 13 disposed about an intermediate portion of the member 11 for vertical reciprocation relative thereto. More particularly, the tubular member 11 has a box end 14 of a tool joint at its upper end and a pin end 15 of a tool joint at its lower end. The box end is adapted to be connected to the pin end of a tool joint on the lower end of drill collar 16 above the keyseat wiper 10, while the pin end 15 on member 11 is adapted to be connected to the box end of a tool joint on the drill collar 17 connected beneath the keyseat wiper. When the tubular member is so connected in the drill string, its bore 18 provides a smooth continuation of the bore through the drill string portions above and below the keyseat wiper.

As best shown in FIGURE 1, the sleeve has a series of spirally arranged cutting blades 18 arranged thereabout. As previously described, these blades ordinarily have an outside diameter greater than that of the largest part of the remainder of the drill string, such as the drill collars 16 and 17. These blades and the sleeve 13 as a 4 whole are shown in FIGURE 1 to be stuck within a keyseat in the well bore 12.

As best ShOWn in FIGURE 2, the intermediate portion of the outside of tubular member 11 is reduced to provide oppositely facing annular shoulders 20 and 21 at its upper and lower ends, respectively. More particularly, the spacing between the sleeves 20 and 21 is greater than the length of the sleeve 13 so that the tubular member may be so manipulated, in a manner to be described, as to impart either a downward or an upward jar to the sleeve 13 for the purpose of freeing same from the keyseat. That is, the upper shoulder 20 on the tubular member is adapted to be jarred downwardly against the upper end 22 of the sleeve 13, while the lower shoulder 21 on the tubular member is adapted to be joined upwardly against the lower end 23 of the sleeve.

The detent mechanism for storing energy in the tubular member 11 comprises a spline extending longitudinally along the mid portion of such member for selective interengagement with the upper and lower portions of a spline extending longitudinally from one end to the other of the inner diameter of the sleeve 13. The latter spline comprises a relatively long central lug 25 and relatively short lugs 24 on opposite ends of the lug 25. More particularly, there is equal vertical spacing between adjacent short lugs 24 as well as between long lug 25 and the short lugs 24 adjacent thereto. Consequently, the upper and lower portions of the spline on the sleeve 13 comprise equally spaced apart notches formed between the lugs on opposite ends of the long lug 25.

The spline on the tubular member 11 comprises equally spaced apart lugs 26 corresponding in number to the notches of the upper and lower portions of the sleeve spline above and below central lug 25. More particularly, the spacing between the lugs 26 is slightly greater than the length of the lugs 24, so that the lugs 26 are adapted to fit rather closely between the lugs on the sleeve between which the notches are formed. Preferably, the lugs 26 are interconnected by a rib 27 on the side thereof opposite that adapted to engage with the spline of the sleeve 13.

As best shown in FIGURES 2 and 3, the inner diameters of the lugs 24 and 25 are just greater than the outer diameter of the reduced portion of the tubular member 11, and the outer diameters of lugs 26 and rib 27 are just smaller than the inner diameter of sleeve 13, so that the annular space between such member and sleeve is of minimum thickness. Also, the lugs 26 and rib 27 of each spline on the tubular member are of a width less than the spacing between the lugs 24 and 25 of the spline on the sleeve, so that, in one relative rotative position of the tubular member and sleeve, the splines on the tubular member 11 are free to move vertically of the sleeve.

In the use of this detent mechanism, the lugs 26 of the splines on tubular member 11 may be moved into engagement with the notches of either the upper or lower portions of the splines on sleeve 13. More particularly, the lugs 26 are so engaged by the imparting of right hand torque to the upper end of the tubular member 11 as the sleeve 13 is fixed against rotation by its engagement within the keyseat. When such lugs are engaged with the upper sets of notches, as illustrated in FIGURE 2, the jarring shoulder 20 is spaced above the upper end 22 of the sleeve 13. Thus, with right hand torque held on the tubular member 11, the weight of the drill string above the keyseat wiper may be slacked off the elevators and the torque gradually released. The lugs 26 thus move out of the notches and into the space between opposite splines on the sleeve 13, whereby the energy stored in the tubular member 11 causes the shoulder 20 to be jarred down against the end 22 of the sleeve.

Conversely, when the tubular member 11 and the lugs 26 thereon are lowered relative to the sleeve so as to dispose the lugs opposite the lower set of notches of the spline of the sleeve 13 and right hand torque is imparted to the tubular member to engage the lugs with the notches, a strain may be taken on the drill string. In this latter position of the tubular member 11 relative to the sleeve 13, the jarring shoulder 21 on its lower end is spaced beneath the lower end 23 of the sleeve 13. Thus, when torque is gradually released from the tubular member 11, the energy stored therein causes it to move upwardly at an accelerated rate and thus cause shoulder 21 to jar against sleeve end 23 with a large force.

The enlarged lug 25 on the sleeve prevents engagement of the lugs 26 on tubular member 11 in a position intermediate their upper and lower positions, although obviously other means may be employed for this same purpose. For example, each spline on the tubular member 11 may comprise only a single lug selectively engageable with a notch formed on each opposite side of a single lug 25 of the spline on the sleeve 13. In this latter case, the single lug of each spline on tubular member 11 would be considerably longer, and preferably as long as the rib 37. As shown, the upper and lower edges of each of the lugs 26 are tapered at a rather small angle to the horizontal so as to both facilitate interengagement with the notches between the lugs 24 and 25 and also to facilitate disengagement of the lugs upon release of the torque in the tubular member 11.

As shown in FIGURE 2, the tubular member 11 includes a tubular section 28 having a sub 29 connected to its upper end. More particularly, the box 14 and the upper jarring shoulder 20 of the upper end of the tubular member 11 are formed on sub 29, while the pin and the lower jarring surface 21 thereof are formed on the tubular section 28.

The upper end of tubular section 28 tapers down to threads 30 engaged by threads 31 about the lower inner diameter of sub 29. Thus, as will be apparent from FIG- URE 2, upon removal of the sub 29, and integral tubular member 32 forming the main portion of the sleeve 13 may be moved downwardly over the upper end of tubular section 28. As can be seen from FIGURE 5, lugs 24 and 25 are formed on the integral member 32, and the recesses between them extend to the bottom of the inner diameter of the section 32 so that the member 32 may be so lowered when these recessed portions are properly aligned with the lugs on the tubular member 11.

As shown in FIGURE 2, the reduced upper portion beneath the end 22 thereof has a groove thereabout to receive a ring 32a of resilient material which forms a sliding seal about the reduced portion of tubular member 11 between jarring shoulder and the upper end of the splines on such tubular member. As shown in FIGURES 2 and 5, the lower end of integral member 32 is enlarged to provide a recess 33 for ring 34 of resilient material adapted to provide a sliding seal with the reduced portion of tubular member 11 between its lower jarring shoulder 21 and the lower end of the splines on the tubular member 11.

This seal ring 34 is backed up by a split washer 35 between the inner side thereof and a shoulder 36 on member 32 at the upper end of recess 33, and is held in place by a split nut 36 threadedly connected to the lower end of recess 33. Mor particularly, the nut 36 engages and compresses the seal ring 34 into sealing engagement between the recess of the sleeve and the reduced portion of the tubular member 11.

In the assembly of the sleeve 13, the seal ring 34 is first moved over the upper end of tubular section 28 and then stretched somewhat to pass over the lugs of the splines thereon. The integral member 32 of the sleeve is then moved down over the upper end of the tubular section with the recessed portions thereof between lugs 24 and to permit it to be moved past them. At this time, sub 29 may be reconnected to the upper end of tubular section 28 so as to retain the member 32 thereon.

The split washer 35 is moved upwardly into the recess 33 and against the shoulder 36, and the seal ring 34 moved upwardly along the reduced portion of tubular member 11 into engagement with the split washer. Then the split nut 36 may be moved into position about the tubular member beneath the lower end of integral member 32 and upwardly into the recess 33. Upon engagement of its threads with those on the lower end of the recess, the nut may be made up to the extent necessary to compress the seal ring into sealing engagement.

The split washer 35 backs up the seal ring 34 by at least substantially bridging the gap at the inner end of the recesses in the member 32 between the lugs 24 and 25, so that pressure within the annulus of the well bore will not blow the seal ring into the space between the tubular member and sleeve. Thus, as shown in FIGURE 5 the Washer is preferably arranged with the split between its parts aligned with the lugs 24 and 25.

Preferably the space between the reduced portion of the tubular member 11 and inside of the sleeve 13 intermediate the upper and lower seal rings 32a and 34 is filled with a substantially incompressible liquid, such as a relatively light oil. This is of assistance in excluding drilling mud and other debris from admission to the space between the seal rings, which might then cause the sleeve to freeze on the tubular member. This space is filled with liquid through a pair of ports 37 formed through opposite end portions of the sleeve 13, and particularly the integral member 32 thereof, and adapted to be closed by plugs 38.

From the foregoing, it will be seen that this invention is one well adapted to attain all of the ends and objects hereinabove set forth, together with other advantages which are obvious and which are inherent to the apparatus and structure.

It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.

As many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. A keyseat wiper, comprising a tubular member connectible in a drill string and including a tubular section having an enlarged end providing one shoulder and a sub removably connected to the opposite end of the tubular section to provide another shoulder, a sleeve including an integral member movable axially over the opposite end of the tubular section and into position about said section when said sub is disconnected therefrom, so that, upon connection of the sub to said tubular section, each end of the sleeve is adapted to be jarred by a shoulder of the tubular member, blades about the outside of the sleeve, a spline extending longitudinally along the inside of the sleeve and having notches therein, a spline extending longitudinally along the outside of the tubular section and having at least one lug thereon for selective engagement with a notch of the spline on the sleeve, upon application of torque to said tubular member in one direction, so as to hold said sleeve and tubular member against relative axial movement, said splines being disengageable and said tubular member being movable axially of the sleeve, upon release of such torque, whereby energy stored in the drill string is free to urge one of its shoulders against an end of the sleeve with a jarring impact, said sleeve having reduced inner diameter portions on its opposite ends, said tubular section having equal outer diameter portions above and below the spline thereon, and means on the reduced diameter portions of the sleeve for sealing about the equal diameter portions of the tubular section.

2. A keyseat wiper of the character described in claim 1, wherein the reduced diameter portion at one end of the sleeve includes an annular recess extending inwardly from the outer end of the integral member of the sleeve, a ring of resilient sealing material receivable within the recess, split rings movable into the recess on opposite sides of the sealing ring, and means for securing the outer split ring to the integral member so as to expand the sealing ring into sealing engagement between the recess and said tubular section.

3. A keyseat wiper of the character described in claim 2, wherein the annular space between the sleeve and tubular section is filled with a relatively incompressible liquid.

References Cited UNITED STATES PATENTS 2/1938 Pyle 175-295 12/1957 Storm 175295 1/1958 Van Note 175-306 X 12/1958 Chadderdon 175-295 8/1965 Womack 175306 X US. Cl. X.R. 

